<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

    <style>
        .one{
            width: 980px;
            height: 200px;
            border: 1px solid #ddd;
            margin: 10px auto;

            /*伸缩盒*/
            display: flex;

            align-items: center;
            justify-content: space-between;
        }

        .one > div{
            border: 1px solid red;
        }

        .one > div:nth-child(1){
            /*扩展量 可以理解为占比*/
            flex-grow: 1;
        }

        .one > div:nth-child(2){
            /*扩展量 可以理解为占比*/
            flex-grow: 1;
        }

        .one > div:nth-child(3){
            /*扩展量 可以理解为占比*/
            flex-grow: 1;
        }

        .one > div:nth-child(4){
            /*扩展量 可以理解为占比*/
            flex-grow: 1;
        }


    </style>


</head>
<body>


<div class="one">
    <div>1</div>
    <div>2</div>
    <div>3</div>
    <div>4</div>
</div>


</body>
</html>